added some gem fixes for capistrano 2

Gemfile

···
   gem 'debug'
   gem 'thin'
   gem 'capistrano', '~> 2.0'
+
+  # for net-ssh & capistrano
+  gem 'ed25519', '>= 1.2', '< 2.0'
+  gem 'bcrypt_pbkdf', '>= 1.0', '< 2.0'
 end
 
 gem 'ostruct'  # for rake, to remove when rake is updated

Gemfile.lock

···
       uri (>= 0.13.1)
     base32 (0.3.4)
     base64 (0.3.0)
+    bcrypt_pbkdf (1.1.1)
     benchmark (0.4.1)
     bigdecimal (3.2.2)
     blue_factory (0.1.5)
···
       reline (>= 0.3.8)
     didkit (0.2.3)
     drb (2.2.3)
+    ed25519 (1.4.0)
     erb (5.0.2)
     eventmachine (1.2.7)
     faye-websocket (0.12.0)
···
 
 DEPENDENCIES
   activerecord (~> 8.0)
+  bcrypt_pbkdf (>= 1.0, < 2.0)
   blue_factory (~> 0.1.5)
   capistrano (~> 2.0)
   debug
   didkit (~> 0.2)
+  ed25519 (>= 1.2, < 2.0)
   irb
   ostruct
   rainbow